Apparatus for the mechanical production of acoustic vibrations for use in emulsification, dispersion or like processes



2,657,021 OF ACOUSTIC DISPERSION CHANI IN LIK ed J W L Amm T m Ewm LWW.a T m E CE c w .E U EH w RF 0 s O NH AA RR m 3 w v 5A 9 1 7 2 .L c O EPROCESSES uly 15, 1952 OR Fil Patented Oct. 27, 1953 APPARATUS FOR THEMECHANICAL PRO- DUCTION OF ACOUSTIC VIBRATION S FOR USE INEMULSIFICATION, DISPERSION OR LIKE PROCESSES Eric C. Cottell, Ilkley,and John E. Goodman, Stanks, Leeds, England Application July 15, 1952,Serial No. 298,978 In Great Britain February 22, 1951 Claims. 1

This invention relates to apparatus for the mechanical production ofacoustic vibrations generally in the ultrasonic range in a mannersuitable particularly for use in the emulsification or homogenisation ofoil and water and suspensions of solid matter in liquids and likepurposes.

The apparatus makes use of the known principle of mechanical productionof ultrasonic or like acoustic vibrations which is used in a liquidwhistle and which consists essentially in causing a jet of liquid toimpinge on a vibratory member so as to produce high frequencyvibrations, but applies this principle in a practical arrangementcapable of being put to numerous industrial uses and particularly in areadily portable form.

According to the invention the apparatus consist in a jet-form structureto which liquid can be supplied under pressure and having one or morerestricted outlets or nozzles which direct the liquid stream against ablade or like vibrator so as to produce acoustic vibrations generally inthe ultrasonic range, the jet-form structure and vibrator being mountedso as to be readily introduced into or close to the medium to betreated.

Preferably a blade or other form of vibrator is mounted on the jet-formstructure which in turn is mounted on the end of the fluid supply pipeor in a frame or on arms and such pipe, frame or arms can be adapted forfixing upon a vessel which is to contain the medium to be treated or canbe swung into and out of working position as desired.

In order that the invention may be clearly understood and readilycarried into eifect the same will now be more fully described withreference to and by the aid of the accompanying drawings, wherein:

Figures 1 and 2 are respectively an elevation and plan of one form ofportable apparatus according to the invention shown mounted on the sideof a mixing pan.

Figure 3 is an elevation mainly in section of the body of the jet-formstructure.

Figure 4 is an elevation of a bell-like nose piece forming the outer endof the jet-form structure.

Figure 5 is a plan of the body shown in Figure 3.

Figure 6 is a transverse section taken on the line A-A in Figure 5showing the detail of the jet-form outlet.

In the illustrated embodiment of the invention a rotary pump l andelectric motor 2 are 2 mounted as a unit in a casing from which dependsuction and delivery pipes 3, 4. The lower end of the delivery pipe 4has connected to it the jet-form structure which may be moulded in asuitable synthetic material or cast in suitable metal.

This jet-form structure is shown as consisting of a body in halves 5, 6with an outer covering 1, or alternatively the two halves can be boltedtogether, the body being connected at the inner end by a union 8 to thedelivery pipe 4 and having an internal passage 9 which is circular atits inner end and gradually flattens out in smooth contours towards theouter end where it forms a slit like outlet l0. This outlet I0 may varysomewhat in shape, but as illustrated its section is represented by theintersection of two circles of the same radius which radius is such thata straight line joining the two points of intersection is in the ratioof 50:1 relative to the height of the rightangular upright drawn fromthe centre of such line to the circumference of one circle. With thedimensions w and t indicated in Figure 6, the diameter of each circlewould be represented by In any event the shape of outlet will bedesigned with the object of producing a jet of liquid best adapted toco-operate with the vibratory blade.

The blade H is preferably made of spring steel of the shape illustratedwith a hollow ground edge on which the liquid jet impinges. This bladeis clamped by narrow strips and screws I2 to two arms l3 formed with orsecured to the body half 6, so that the blade is free to vibrate at itsown frequency without support along its sharpened edge.

A resonant bell or nose piece I i can be screwed onto the threaded endsof the body halves to surround the blade and its mounting, and this bellhas its internal bore reduced to form an open circular end It of adiameter approximately equivalent to the length of the jet-form outletI0. By this means the eiiect of the vibration may be amplified and acavity maintained in the bell by the ejector eifect of the liquidpassing at high speed across the blade and through the bell. This maymaintain the velocity of the jet across the blade at a faster rate thanif it were immersed in the liquid without the bell attached, owing tothe inertia of the liquid itself slowing down the jet when it is notpassing through the bell.

The casing of the motor 2 is shown with a swivel bracket [6 by which thewhole apparatus can be pivotally mounted on the side of a pan or likevessel I1 to contain the liquid to be treated and this bracket caninclude readily detachable clamping means to enable the apparatus to bemoved at will. The apparatus can be counterbalanced by suitable means(not shown) so as to be readily lowered into the vessel. Alternativelythe apparatus would be arranged for suspending above the vessel andlowering into it.

It is intended generally to operate the apparatus with the outlet andblade below the liquid level in the vessel, though it may operate justabove the surface with the suction pipe 3 dipping below.

When operating with the apparatus the mixture is drawn into the pump andthen expelled through the jet-form outlet at a pressure (say) of from130 to 300 lbs., per square inch, impinging on the blade and deflectingit. The elasticity of the blade itself restores it to its normalposition and it is again deflected in the opposite direction. This cyclecontinues at very high speed and ultrasonic oscillation results.Cavitation at the blade tip causes violent agitation of the liquid andconsequent emulsification or such like due to very high pressuresrealised on the collapse of the cavities.

The pump can be provided with a by-pass to vary its capacity and,therefore, the pressure and intensity of the oscillations produced.

As an alternative a thick blade of concave wedge or other shape may bemounted on a torsion bar which would allow the blade to vibrate althoughtoo thick to oscillate due to its own elasticity. In such case therewould be less likelihood of the blade breaking through fatigue.

It is believed that an apparatus according to the invention will be ofmore simple and compact construction than any at present employed inindustry, and may have an extensive application in the pharmaceutical,cosmetic, textile, food. mineral preparation, brewing, oil, engineeringand other industries.

Practical tests indicate that the apparatus will absorb only a smallfraction of the power needed by equivalent emulsifiers of conventionaltypes and its efficiency will enable less emulsifying agent to be usedand produce a very finely divided suspension.

We claim:

1. Apparatus for producing emulsification or homogenisation of oil andwater and suspensions of solid matter in liquids and like purposes bymechanically produced acoustic vibrations in or near the ultrasonicrange, comprising in combination a jet-form structure having at leastone restricted outlet or nozzle, a blade-like vibrator element having atleast a portion thereof supported for vibratory movement and locatedwith its thin edge in line with said outlet, means for passing theliquid to be treated under pressure through said jet-form structure andagainst the thin edge of said vibrator element so as to produce theacoustic vibrations, and means for introducing said jet-form structureand vibrator element into or close to the medium to be treated.

2. Apparatus for producing emulsification or homogenisation of oil andwater and suspensions of solid matter in liquids and like purposes bymechanically produced acoustic vibrations in or near the ultrasonicrange, comprising in combination a jet-form structure having at leastone restricted outlet or nozzle, a blade-like vibrator element having atleast a portion thereof capable of vibratory movement and mountedonsaidstructure with its thin edge in line with said outlet, means for passingthe liquid to be treated under pressure through a delivery pipe on whichsaid structure is mounted and through said structure and against thethin edge of said vibrator element so as to produce the acousticvibrations, and means for supporting said delivery pipe, jet-formstructure and vibrator element in connection with a vessel which is tocontain the medium to be treated so as to be capable of readily beingmoved into and out of working position.

3. Apparatus as called for in claim 2, including a jet-form structurehaving an internal passage which changes by smooth contours from asubstantially circular inlet at the inner end to a slit-like outlet atthe outer end, and a vibratory blade located substantially in the planeof said slit-like outlet so as to receive the jet of liquid against itsfree edge.

4. Apparatus as called for in claim 2, including a jet-form structurehaving an internal passage which changes by smooth contours from asubstantially circular inlet at the inner end to a slit-like outlet atthe outer end, and a vibratory blade located substantially in the planeof said slit-like outlet sov as to receive the jet of liquid against itsfree edge and a resonant bell or nose piece applied to the outer end ,ofsaid jet-form structure and surrounding said blade and its mounting andhaving a circular opening in its outer end of a diameter approximatelyequivalent to the length of the jet-form outlet.

5. Apparatus for producing emuls fi n Qr homogenisation of oil and waterand suspensions of solid matter in liquids and like purposes bymechanically produced acoustic vibrations in or near the ultrasonicrange comprising in combination an electric motor and a pump driventhereby mounted as a unit, a suction pipe and a delivery pipe connectedto and supported from said pump, a jet-form structure mounted on theouter end of said delivery pipe and having an internal passage whichchanges by smooth con-.- tours from a substantially circular inlet atthe inner end to a slit-like outlet at the outer end, a thin vibratoryblade clamped by its thicker edge to two arms projectin forwards fromsaid jet-form structure and located with its sharpened edge opposite andparallel to said slit-like outlet so as to be vibrated by the liquid jetimpinging on it, a resonant bell or nose piece applied to the outer endof said jet-form structure and surrounding said blade and its mountingand having a circular opening in its outer end of a diameterapproximately equivalent to the length of said slit-like outlet, anddisengageable means for supporting the complete apparatus in connectionwith a vessel to contain the liquid to be treated with the suction pipedipping into said liquid and for enabling said apparatus to be loweredinto and raised out of working position.

ERIC C. COTTELL. JOHN E. GOODMAN.

References Cited in the file of this patent UNITED STATES PATENTS 7Number Name Date 1,445,427 Werner Feb. 13, 1923 1,678,225 Kincade July24, 1928 2,005,800 OBoyle "June 25, 1935

